ABOARD CYCLOPS 1, ELLIOTT BAY—I catch a last, harbor seal’s glimpse of the Seattle Aquarium and downtown skyline beyond through the dome-shaped hatch of the submersible. The pilot turns on the life support systems and opens a valve. Air releases from the ballast tank with a gasp.

“OK, everybody, we’re going to go under,” says Stockton Rush at the controls of Cyclops 1, a prototype for what he hopes will set a new standard for comfort and versatility in manned undersea exploration.

The light of a high-noon summer sun penetrates through the first few feet of water, casting a surreal green glow into the sub as we descend, rolling gently as it finds its underwater equilibrium.

In addition to the clear dome in the conning tower, there is a convex window in front that is the full diameter of the Chevy Suburban-sized vessel. It bulges eyelike out into the water, affording a fantastic view, a sense of spaciousness greater than its actual volume, and giving the Cyclops its name.

Dana Wilkes, marine operations director at NOAA for U.S. National Marine Sanctuaries, and Joe Downes from Senator Maria Cantwell’s office sit with their stocking feet extending into the eye. I’m on a comfortable rubber mat behind them with Gus Gates, Washington policy manager with the Surfrider Foundation. Rush is behind us, surrounded by a couple dozen lights and switches, holding a PlayStation controller and staring intently at a flatscreen monitor.

Underwater, and inside the thick, cylindrical steel hull of Cyclops 1, a cacophony of strange sounds: whirring thrusters, the beep-beep of a tracking signal, the tinny hush of communications equipment, and boats passing overhead, which sound almost like someone is hosing down the sub from the outside.

Cyclops 1 incorporates interior features such as LED lighting, simplified controls, and an open layout, which OceanGate hopes will make long dives for research, infrastructure inspections, testing, filming, and other endeavors easier to endure. The company has invited a range of guests, including media, to dive in its subs as it builds publicity for its intended business of chartering them to a range of industries.

This was my first time in an underway submersible. I’m not generally prone to claustrophobia and didn’t experience it here. During nearly three hours closed in the sub with four other people, I was comfortable throughout. Any anxiety about going underwater in a vessel that’s “still in the development stage,” as Rush reminded us during a pre-dive briefing, was quickly replaced by a sense of calm and wonder at this new perspective on Puget Sound.

Wilkes, a veteran of undersea research missions conducted with manned submersibles and by SCUBA divers, says the comfortable confines facilitate data collection and note taking. There’s also something about putting researchers in near-direct contact with their subject matter, rather than forcing them to work through the intermediary of a remotely operated vehicle. “Their mind just explodes,” Wilkes says.

Rush controls the sub’s four Innerspace 1002 electric thrusters with a modified PlayStation controller like the one you’d use to play Grand Theft Auto. He navigates using a high-resolution sonar system, as well as visual cues from a forward-facing camera and a little squid-shaped, neutral-buoyancy fishing lure mounted just outside the eyelike window. It indicates the direction the sub is moving through the water. Later, when it’s my turn at the controls, I add touch to the mix of inputs, bumping the sub’s skids into the muck of a narrow undersea canyon.

Our initial descent takes us about 54 feet below the surface. We are looking for a large metal bait cage that has been used in the past to attract sixgill sharks. The sonar display on the flatscreen monitor lights up with several bright dots in a triangle pattern. It’s the pilings that support the aquarium. And then we spot the bait box. Rush nudges Cyclops closer. The barnacle-encrusted box is mostly empty, home to a crab and some sea anemones.

We turn away from the aquarium, heading deeper. The water is darker and thick with plankton, floating like stars.

“We lost our sonar,” Rush calmly informs us. He gently settles the sub on the bottom to reboot, but the picture it paints is less clear than before. The multi-beam sonar system, when functioning properly, allows the pilot to navigate and see things like fishing lines and other small objects that could snag the sub.

When it’s working again, Rush points the sub to the west toward the canyon. He calls out objects as they appear on the sonar, and we try to visually identify them through the dark and silt kicked up by the thrusters. We pass an old, corroded pipe, and more sea anemones. Later, we see antique-looking bottles, possibly dropped by drunken sailors at anchor here who knows how long ago. (Closer to the seawall, there were modern beer bottles on the bottom.)

The sonar shows blips that look like a school of larger fish, but they swim away before we can see them. We make out a spotted ratfish, a sole of some kind, tiny bottom-dwelling gobies, a spot prawn.

Rush offers each of us a turn piloting the sub, using the Bluetooth-connected controller. It takes some time to calibrate my joystick movements. Subtlety is the key. The sub, weighing around 19,000 pounds, has a lot of momentum once it gets going. Those countless hours playing video games suddenly seem like useful experience as I manage to keep Cyclops 1 under control, hovering just off the bottom, following a steep slope down through 130 feet of black water.

It’s time to return to the surface. We rise steadily, racing bubbles back up through the black, then green, then bursting into the brilliant blue.